Non-contact scanning system

ABSTRACT

A non-contact scanning system for three dimensional non-contact scanning of a work piece is disclosed for use in various applications including reverse engineering, metrology, dimensional verification and inspection The scanning system includes a scanner carried by an arcuately configured gantry assembly and a fixture for carrying a work piece. The gantry assembly includes a fixed arcuately shaped gantry member and a telescopic arm that is movable in an arcuate direction relative to a rotary table that carries the object to be scanned. A scanner is mounted on the end of the telescopic member and is movable in a radial direction. Objects to be scanned are mounted on a rotary table that is also movable in an X-Y direction or alternatively in the X, Y and Z directions under the control of a motion control subsystem, a machine control user interface subsystem and an image capture. The configuration of the scanning system in accordance with the present invention provides a spherically shaped scanning envelope which facilitates three dimensional modeling of the work piece.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a non-contact scanning system and moreparticularly to a three dimensional non-contact scanning system for usein various applications including reverse engineering, metrology,dimensional verification and inspection, which includes a scannerassembly carried by an arcuately configured gantry assembly and afixture assembly for carrying the work piece and enabling an sphericallyshaped scanning envelope to facilitate the formation of a threedimensional model of an object or work piece.

2. Description of the Prior Art

Various scanning systems are known in the art for scanning objects foreither dimensional verification or reverse engineering of a work piece.Examples of such systems are disclosed in U.S. Pat. Nos. 5,784,282;5,848,115; 5,999,642; 6,028,955; 6,031,225; 6,101,268; 6,226,395;6,285,959; 6,542,249; 6,570,715; 6,571,008; 6,628,819; 6,687,328;6,703,634, 6,708,071; 6,738,507; 6,834,253; 6,850,331; 6,912,293 and6,917,701, hereby incorporated by reference. Such systems normallyinclude a movable fixture for carrying the work piece and a stationaryor movably mounted scanner for scanning the work piece. Many knownscanners are used for three dimensional scanning of an object. Forexample, U.S. Pat. No. 5,848,115 discloses a three dimensional scanningsystem which utilizes computerized tomography, used for dimensionalverification of a work piece. The scanning system includes an x-raysource and detector (hereinafter referred to as an “x-ray scanner”)mounted to a gantry which allows the scanner to move linearly along theX and Z axes. The work piece to be scanned is mounted on a fixture thatincludes rotatable table which is also mounted for rectilinear movementalong the X and Y axes. U.S. Pat. Nos. 5,999,642; 6,101,268; and6,226,395 also illustrate a three dimensional scanning system whichincludes a scanning device (in this case a camera) mounted on a gantrywhich allows the scanning device to move linearly along the X, Y and Zaxes relative to the object to be scanned. U.S. Pat. No. 6,628,819discloses a three dimensional scanning system which includes a fixturefor carrying a work piece to be scanned, formed as a rotatable table.The scanner is fixed relative to the rotatable table so that locatormarkings on the rotatable data are always in the field of view of thescanner. U.S. Pat. No. 6,687,328 also discloses a three dimensionalscanning system which includes an x-ray scanner mounted for movementrelative to the X-Y axes. The scanning system also includes a fixturefor carrying the work piece to be scanned. The fixture is mounted underthe platform and is configured to be rotated about the X and Y axes.

The configurations of the three dimensional scanning systems mentionedabove constrain the size the work piece that can be scanned. In order tosolve this problem, U.S. Pat. No. 6,738,507 discloses a threedimensional free standing scanning system for imaging relatively largeobjects on the ground or in situ. This scanning system includes ascanners mounted at the end of a free standing robot arm configured withmultiple degrees of freedom that allows the scanner to scan the objectfrom many different positions and angles.

The configurations of the various three dimensional scanning systemsmentioned above also result in other problems. For example, suchconfigurations require multiple scans in order to form a threedimensional model of the work piece. As such, these systems requirecomputationally intensive calculations to spatially orientate each ofthe two dimensional images from the scanner in order to form a threedimensional model of the work piece. Thus there is a need to provide athree dimensional scanning system which facilitates formation of a threedimensional model of the work piece.

SUMMARY OF THE INVENTION

The present invention relates to a non-contact scanning system for threedimensional non-contact scanning of a work piece for use in variousapplications including reverse engineering, metrology, dimensionalverification and inspection The scanning system includes a scannercarried by an arcuately configured gantry assembly and a fixture forcarrying a work piece. The gantry assembly includes an arcuately shapedgantry member and a telescopic member that is movable in an arcuatedirection relative to a rotary table that carries the object to bescanned. A scanner is mounted on the end of the telescopic member and ismovable in a radial direction. Objects to be scanned are mounted on arotary table that is also movable in an X-Y direction or alternativelyin the X, Y and Z directions under the control of a control system. Theconfiguration of the scanning system in accordance with the presentinvention provides a spherically shaped scanning envelope whichfacilitates three dimensional modeling of the work piece.

DESCRIPTION OF THE DRAWING

These and other advantages of the present invention will be readilyunderstood with reference to the following specification and attacheddrawing wherein:

FIG. 1 is an isometric view of one embodiment of the non-contactscanning system in accordance with the present invention which includesa fixture assembly movable in the X and Y directions.

FIG. 2 is a side view of the non-contact scanning system illustrated inFIG. 1, with a portion of the base partially broken away illustrating anarcuately configured gantry assembly in section and further illustratingthe semi-spherical scanning envelope of the scanning system.

FIG. 3 is a front view of the non-contact scanning system illustrated InFIG. 1 which also illustrates the system's scanning envelope.

FIG. 4 is a top view of the non-contact scanning system, illustrated inFIG. 1

FIG. 5 is an exploded isometric view of the non-contact scanning systemillustrated in FIG. 1.

FIG. 6 is an isometric view of an exemplary fixture assembly, configuredto provide linear movement to a work piece in a direction parallel tothe X, Y and Z axes as well as rotary movement about the Z axis.

FIGS. 7A and 7B are isometric views of an exemplary gantry assemblyconfigured with a manual actuator.

FIG. 7C is an isometric view of an exemplary gantry assembly shown insection, illustrating only the radius arm and the telescopic member inaccordance with the present invention.

FIG. 7D is an enlarged view of a portion of the gantry assemblyillustrated in FIG. 7B.

FIGS. 8A-8C are isometric views of a portion of the fixture assemblywith exemplary drive mechanisms to provide linear movement of a workpiece in a direction parallel to the X and Y axes and rotary movementabout the Z axis.

FIG. 9A is a more detailed front view of the non-contact scanning systemillustrated in FIG. 1, illustrating different positions of the fixtureassembly relative to an X axis.

FIG. 9B is a more detailed side view of the non-contact scanning systemillustrated in FIG. 1, illustrating different positions of the fixtureassembly relative to a Y axis and different arcuate positions of thegantry arm assembly.

FIG. 10A is a perspective view of an alternate embodiment of anon-contact scanning system in accordance with the present inventionthat includes a fixture assembly that is movable in the X, Y and Zdirections and a scanner assembly that has three degrees of freedom.

FIG. 10B is an exploded isometric view of the non-contact scanningsystem illustrated in FIG. 10A.

FIG. 11A is another alternate embodiment of the non-contact scanningsystem that includes a fixture movable in the X, Y and Z directions.

FIG. 11B is an exploded isometric view of the non-contact scanningsystem illustrated in FIG. 11A.

FIG. 12 is a partial isometric view of a non-contact scanning system inaccordance with the present invention, shown connected to a hostcomputer.

FIG. 13 is a block diagram of the non-contact scanning system inaccordance with the present invention.

FIG. 14 is a flow diagram of a motion control subsystem, which forms apart of the present invention, illustrating the operation, control,start-up and shut down sequences.

FIG. 15 is a flow diagram of a machine control user interface subsystem,which forms a part of the present invention, illustrating the operation,control, start-up and shut down sequences of that subsystem.

FIG. 16 is a flow diagram of the machine control user interfacesubsystem job file management commands.

FIG. 17 is a flow diagram of the machine control user interfacesubsystem job file playback commands.

FIG. 18 is a flow diagram of the scanner status query command.

FIGS. 19A and 19B is a flow diagram of machine control user interfacesubsystem motion control commands.

FIG. 20 is a flow diagram of machine control user interface subsystemmotion control and image capture commands.

FIG. 21 is a flow diagram of a motion control subsystem status querycommand.

DETAILED DESCRIPTION

The present invention relates to non-contact three dimensional scanningsystem for use in various applications, including reverse engineering,metrology, dimensional verification and inspection. The scanning systemincludes a scanner carried by an arcuately configured gantry assemblyand a fixture for carrying a work piece. The scanning system includes ascanner carried by an arcuately configured gantry assembly and a fixturefor carrying a work piece. The gantry assembly includes an arcuatelyshaped radius arm and a telescopic member that is movable in an arcuatedirection relative to a rotary table that carries the object to bescanned. A scanner is mounted on the end of the telescopic member and ismovable in a radial direction. Objects to be scanned are mounted on arotary table that is also movable in an X-Y direction or alternativelyin the X, Y and Z directions. The configuration of the scanning systemin accordance with the present invention provides a spherically shapedscanning envelope which facilitates three dimensional modeling of thework piece.

Three exemplary embodiments are described and illustrated. Moreparticularly, FIGS. 1-9 illustrate a first embodiment of the non-contactscanning system which includes a fixture carried by a base whichincludes a rotatable table that is also configured for movement in the Xand Y directions. FIGS. 10A and 10B illustrate a second embodiment,similar to the embodiment illustrated in FIGS. 1-9, but with a fixtureassembly that is configured for movement along the X, Y and Z directionsand a manually movable scanner assembly that has three degrees offreedom. FIGS. 11A and 11B illustrate a third embodiment similar to theembodiment illustrated in FIGS. 10A and 10B, but with a fixture that issupported with a frame.

First Embodiment

Referring first to FIGS. 1-9, the non-contact scanning system isgenerally identified with the reference numeral 30. The non-contactscanning system 30 includes a fixture assembly, generally identifiedwith the reference numeral 32, for carrying a work piece or object to bescanned 33 and a scanner assembly 40. In this embodiment, the fixtureassembly 32 is configured with two degrees of freedom; namely,rectilinear movement relative to the X and Y axes. The scanner assembly40 is configured with a single degree of freedom; namely, arcuatemovement in a radial direction, relative to the work piece 33.

The fixture assembly 32 is carried by a base 34, configured, forexample, as a rectangular box, for carrying the fixture assembly 32. Thefixture assembly 32 includes a rotatable table 36, for example, acircular table, for carrying the work piece 33. The rotatable table 36is mounted for rotation about a Z axis. The rotatable table 36 ismounted to a rotary drive bracket 38, which, in turn, is also configuredfor rectilinear movement relative to the X and Y axes.

The scanner assembly 40 includes a scanner 42, for example, a camera,for example, a Model No. Comet 250 as manufactured be Steinbechler GmbH.The scanner 42 is securely mounted to a focusing slide assembly 44,configured for radial movement relative to the work piece 33, as bestshown in FIG. 2. In accordance with an important aspect of theinvention, the focusing slide assembly 44, in then, is carried by thegantry assembly 46, which is configured for arcuate movement relative tothe work piece, as best shown in FIG. 2.

As best shown in FIG. 2, the gantry assembly 46 includes a radius arm50, carried by the base 35. The radius arm 50 is configured to slidablyreceive a telescopic member 54. The radius arm 50 may also be configuredto be slidably received in the base 35 to enable the radius arm 50 to beextended to an extended position, as shown in FIGS. 7A and 7B, andretracted to a retracted position, as generally shown in FIG. 2. Thescanner assembly 40 is mounted to one end of the telescopic member 54.Such a configuration allows for an arcuate scanning envelope 48, forexample, a spherically shaped scanning envelope, as shown in FIGS. 2 and3, which facilitates three-dimensional modeling of the work piece.

An exemplary embodiment of the non-contact scanning system 30 isillustrated in FIG. 5. In this embodiment, the base 34 is formed with apair of spaced apart tracks 56 and 58, disposed generally parallel tothe Y axis. The tracks 56 and 58 are configured to slidably receive asliding bracket 60. In particular, the sliding bracket 60 includes apair of spaced apart extending ribs 62 and 64, formed on the undersideof the slide bracket 60. The ribs 62 and 64 are configured to bereceived in slots 56 and 58, formed in the base 34, to enable thesliding bracket 60 to move in a direction parallel to the Y axis. Thetop side of the sliding bracket 60 is formed with a pair of spaced apartslots or tracks 66 and 68, formed generally parallel to the X axis. Thetracks 66 and 68 enable rectilinear movement of the rotary drive bracket38 relative to the X axis. More particularly, the under side of therotary drive bracket 38 is also formed with a pair of extending ribs 70and 72 that are configured to be received in the tracks 66 and 68 formedon the top side of the sliding bracket 60 to enable rectilinear movementof the sliding bracket 60 in a direction parallel to the X axis.

As shown in FIGS. 8A-8C, lead screw mechanisms may be used to drive thesliding bracket 60 along the Y axis as well as the rotary bracket 38along the X-axis. Motors (not shown) may be mounted to motor mountsjustaposed adjacent the lead screw mechanisms for automated movementrelative to the X and Y axis.

The rotary drive bracket 38 includes a central aperture 74. The centralaperture 74 is adapted to receive a shaft (not shown) formed on theunder side of the rotating table 36. The shaft may be connected to agear mechanism, for example, as illustrated in FIG. 8A, to enable therotary drive bracket 38 to rotate about the Z axis. A motor (not shown)may be mounted to motor mount, juxtaposed adjacent the gear mechanismfor automated rotary movement. Such a configuration enables rotarymovement of a work piece 33 carried by the table 36 as well asrectilinear movement in directions parallel to the X and Y axes.

The gantry assembly 46 includes a radius arm 50 that is slidably carriedby the base 35. In particular, the base 35 is configured to slidablycarry the radius arm 50. An exemplary configuration for the gantryassembly 46 is illustrated in FIGS. 7A-7D. referring first to FIGS. 7Aand 7B, a gantry assembly 46 is illustrated and includes a base 35formed with a pair of spaced-apart side walls 37 and 39. One or morepins 41, 43 are used to connect the spaced-apart side walls 37, 39together, as shown. Additionally, a plurality of rollers 45, 47 may berotatably attached to the inside surfaces of the side walls 37 and 39which act as a support and guide for the radius arm 54 as it is moved toan extended position as shown in FIG. 7B and a collapsed position asgenerally shown in FIG. 2. An idler axle 51 may be also provided whichincludes a pair of spaced-apart pinion gears 53, used to drive a pair ofspaced-apart gear racks 55 a and 55 b formed on the arm of thetelescopic member 50. A drive axle 57 is provided that is connectedbetween the spaced-apart side walls 37 and 39. The drive axle 57 isprovided with a pair of spaced-apart pinions 61 a and 61 b, used todrive the gear racks 61 a, 61 b formed on the underside of the radiusarm 50. As shown in FIG. 7A, a manual actuation arm 63 in combinationwith a gear reducer 65 may be used to manually extend and retract theradius arm 50. Alternatively, a motor (not shown) may be attached to agear box (not shown) for automated movement of the radius arm 54 andtelescopic member 50.

Referring to FIGS. 7C and 7D, the radius arm 50 is formed with a pair ofspaced-apart side walls 63 and 65. A plurality of rollers, generallyshown in FIGS. 7C and 7D and identified with the reference numeral 67,are used to guide the telescopic member 50 within the radius arm 50.

Operation of the telescopic member 54 may be controlled by way of a pairof cables 67 and 69 attached to the base 35. As best shown in FIG. 7B,the telescopic member 54 includes a sheave wrap 71 and a cable stay 73.The cables 67, 69 are wrapped around the sheave wrap 71 on each side ofthe telescopic member 54 and attached to the cable stays 73. Thus, asthe radius arm 50 is extended from the base 35, the cables 67, 69 causethe telescopic arm 54 to be extended as well. As the radius arm 50 isretracted into the base 35, the telescopic member 54 retracts into theradius arm 50. The configuration enables arcuate movement of thetelescopic member 54 and radius arm 50 in order to provide a arcuatelyshaped scanning envelope 48 (FIG. 2).

One end 78 of the telescopic member 54 is configured to receive thescanner assembly 40. The scanner assembly 40 includes a slide retainer80 and a slide 82. The slide retainer 80 is stationary mounted relativeto the telescopic member 54. The slide retainer 80 is configured toslidably receive the slide 82 to enable radial movement relative to thework piece 33, for example, by way of a conventional rack and pinionarrangement, not shown, which may be motorized in the same manner asdiscussed above. The scanner 42 is rigidly mounted to one end of theslide 82. The configuration allows radial movement of the scanner 42 inorder to allow the scanner 42 to be focused relative to the work piece33.

FIG. 9A illustrates an exemplary range of motion of the fixture assembly32 in a direction parallel to the X axis. FIG. 9B illustrates anexemplary range of fixture assembly in a direction parallel to the Yaxis. FIG. 9B also illustrates an exemplary range of motion of thetelescopic member 54 in an arcuate direction as well as an exemplaryrange of motion of the scanner 40 in a radial direction with respect toa work piece 33 (FIG. 2).

Second Embodiment

The second embodiment of the non-contact scanning system is illustratedin FIGS. 8A and 8B and generally identified with the reference numeral90. In this embodiment, the fixture assembly, generally identified withthe reference numeral 92, includes a rotatable table 94 with fourdegrees of freedom; rectilinear movement parallel to the X, Y and Z axesand rotary movement about an axis parallel to the Z axis. In thisembodiment, the scanner assembly 96 is mounted on one end of a gantryarm 98 that is mounted for rotation about an axis parallel to the Yaxis. The scanner assembly 96 is configured to provide two additionaldegrees of freedom: rotary movement relative to the X axis and radialmovement relative to the work piece 33.

The fixture assembly 92 includes a lift assembly 100 that is carried bya base 102. The lift assembly 100 includes bottom frame member 104 and atop frame member 106. A pair of scissor mechanisms 108 and 110, forexample, as illustrated in FIG. 6, may be used to couple the top framemember 106 and the bottom frame member 104 together and enable thedistance between the top frame member 106 and the bottom frame member104 to be varied A conventional lift table with integral scissormechanisms may be used, for example, a Backsaver Lite lift table, asmanufactured by Southwork Products.

The top frame member 106 is formed with a pair of spaced apart tracks112, 114, generally parallel to the Y axis. The tracks 112, 114 areconfigured to receive a sliding bracket 116. In particular, the bottomside of the sliding bracket 116 is formed with a pair of spaced apartribs 118 and 120, configured to be received in the tracks 112 and 114 toenable the sliding bracket 116 to move in a direction generally parallelto the Y axis.

The fixture assembly 92 also includes a rotary drive bracket 122,coupled to the slide bracket 116 a similar manner as described above formovement in a direction generally parallel to the X axis. The fixtureassembly 92 also includes a table 124 that is rotatably coupled to therotary drive bracket 122 in a similar manner as discussed above forrotary movement about an axis generally parallel to the Z axis.

In this embodiment, the scanner assembly 96 includes a one-piecearcuately shaped gantry arm 98. The gantry arm 98 is configured forrotary movement about the Y axis. In particular, one end of the gantryarm 98 is formed with an axle 124. The base 102 is formed a slot 126with the width selected to similar to the length of the axle 124 so asto cause a friction fit and enable the gantry arm 98 to rotate relativeto the Y axis.

The other end of the gantry arm 98 is used to carry the scanner assembly96. The scanner assembly 96 includes a slide retainer 128 for receivinga slide 130. As mentioned above, the slide retainer 128 and slide 130allow for radial movement relative to a work piece 33 (FIG. 2).

A scanner bracket 132 is mounted on one end of the slide 130 for rotablycarrying a scanner 133. The scanner bracket 132 is formed as a u-shapedmember with a pair of spaced apart arms 134 and 136. An extending end ofeach of the arms 134 and 136 is formed with an inwardly facingprotuberance (not shown) that are adapted to be received in apertures138 in the scanner as shown to enable the scanner 133 to rotate relativeto the X axis.

Third Embodiment

A third embodiment of the non-contact scanning system in accordance withthe present invention is illustrated in FIGS. 11 and 11B and generallyidentified with the reference numeral 140. The non-contact scanningsystem 140 includes a fixture assembly, generally identified with thereference numeral 142, carried by a frame 144. The non-contact scanningsystem 140 also includes a gantry assembly 146 and a scanner assembly148. The fixture assembly 142 is similar to the fixture assembly 92,illustrated in FIGS. 10A and 10B and provides four degrees of freedom.The scanner assembly 148 is similar to the scanner assembly 96,illustrated in FIGS. 10A and 10B and is configured to enable radialmovement of the scanner relative to a work piece 33 for focusing and isalso configured for rotary movement about the X axis.

The scanner assembly is mounted to a free end of a telescoping arm 150of the gantry assembly 146. The gantry assembly 146 also includes aradius arm 152, formed with a slot 154 for slidably receiving thetelescopic member 150, for example, in a manner as discussed above . . .. In this embodiment, the radius arm 152 is carried by a radius arm base156, which, in turn, is carried by a separate frame 158. A controller160, for example, a Siemens Model NSPP, used for controlling the gantryassembly 146 is also carried by the frame 148. The gantry assembly 146provides an additional degree of freedom for the scanner; namely arcuatemovement relative to the work piece 33 in order to a spherically shapedscanning envelope.

Control System

FIG. 12 is an exemplary embodiment of a non-contact scanning system 160,shown connected to a host computer system 162. A block diagram of thecontrol system is illustrated in FIG. 13. Software flow diagrams for thecontrol system are illustrated in FIGS. 14-21.

Turning to FIG. 12, the non-contact scanning system 160 includes amotorized fixture assembly 166, a gantry assembly 168 and a scannerassembly 170. The non-contact scanning system 162 is controlled by acontrol system which includes a motion control subsystem, an imagecapture subsystem, a motion control user interface subsystem and a hostcomputer system 164.

The motion control subsystem 171 includes one or more motion controlmodules, and other circuitry, as illustrated In FIG. 11, mounted on anenclosed panel 172, either formed as part of the non-contact scanningsystem 162 or remote from it. The motion control subsystem 171 isinterfaced to the host computer system 164 via a communication link. Forexample, a cable 174 may be used to connect the motion control subsystem171 directly to an on-board Serial Port, Parallel Port, USB Port andEthernet Port on the host computer system 164 or indirectly by wirelessmeans. FIGS. 12 and 19 are software flow diagrams illustrating controlof the motion control subsystem 171 by the host computer system 164.

The image capture control system may include a dedicated image capturecontrol card (not shown), an image capture device 176 and an imagecapture and reconstruction program, for example, Polyworks Version 9 orbetter by Innovmetric. A conventional image capture control card, forexample, normally included with the scanner as discussed above, may beconnected to an expansion slot in the host computer system 164. Aconventional scanner, for example, as discussed above, forms part of thescanner assembly, as discussed above. The function of the image captureand reconstruction program is to facilitate control of the image capturedevice and the manipulation and reconstruction of captured images of anobject to create a 3-D model of the object. A cable 175 may be used toconnect the image capture device 176 to the host computer system 164.FIG. 16 is a flow diagram of the scanner status query command.

The motion control user interface subsystem provides the user interfaceand control of the non-contact scanning system 162. In particular, themotion control user interface subsystem includes the user interfaces tocontrol the motion of the fixture subsystem 166 and the gantry subsystem168 via the motion control subsystem 171, and to facilitate internalcommunication between the host computer system 164 and the image capturesubsystem to indirectly control the image capture device.

The motion control user interface subsystem includes motion control userinterface program which runs on the host computer system 164, which mayinclude various user input devices, such as a key board 178 and a mouse180 or other input devices. The motion control user interface subsystemmay also include various user interfaces to the motion control subsystem171 such as, a panel mounted on-off switch with an indicator 182, anemergency stop switch 184 and one or more machine status indicatinglights 186. The motion control user interface program constitutes anumber of software programs to enable the host computer system toexecute a number of commands as illustrated in FIGS. 15, 16, 19A, 19Band 20 and described below.

The non-contact scanning system can operate in one of three Modes ofOperation, to control initialization, idle state, image capture and JobFile, playback mode. The Job File has two functions: 1) is tosequentially store all the fixture assembly axis position after an imageis captured, and to reference the captured image to that position, and2) to automatically send a sequence of commands to the motion controlsubsystem and an image capture subsystem, under motion control userinterface program control, to position the image capture device. This isso images of a similar object can be captured at the same positions asthat of the original object.

Non-Contact Scanning System Modes of Operation

1. Initialization Mode

2. Idle Mode

3. Image Capture Mode

4. Playback Mode

Initialization Mode

Referring to FIG. 14, the initialization mode occurs as a result ofpower-up of the motion control subsystem 171 and the host computersystem 164 as indicated in step 200. Ether the motion control subsystem171 or host computer system 164 can be turned ON first. The system keepschecking in step 202 to determine whether the power to the motioncontrol subsystem 171 has been turned ON, a motion control subsystem ONstate is asserted in step 204 to inform the host computer system 164 ofits' ON state. The system then proceeds to step 206 and waits for anInitialization command from the host computer system 164. As will bediscussed below in connection with FIG. 13, after the host computersystem 164 is powered up, it loads and runs the motion control userinterface program. During execution of that program, the system checksif the motion control subsystem 171 has asserted its' ON state. If so,an Initialization Command is sent to the motion control subsystem 171.After receipt of the Initialize command, the motion control subsystem171 performs its initialization and asserts its Ready State in step 208.After the ready state is asserted, the system waits for the motioncontrol subsystem 171 to be turned off in step 210.In the mean time, thesystem checks in steps 212 and 214 for query and motion commands andexecutes those commands in step 216. Once the motion control subsystem171 is turned off, a motion control subsystem off state is asserted instep 218.

Idle Mode

This mode is in effect after the system has completed its initializationsequence and is sitting idle, waiting for commands to be entered by theuser via the various host computer system input devices. As discussedabove in connection with FIG. 14. In this mode, Job File Management,Motion Control, and Motion Control+Image Capture commands can be enteredand executed. Commands can be entered by the user, via the keyboard 178(FIG. 12), mouse or trackball 180, or other input device.

Referring to FIG. 15, the system waits for the power to be turned on instep 220. After the power is turned on, the system loads and runs themotion control user interface program in step 222, as discussed above.Subsequently in step 224, the system checks whether the motion controlsubsystem ON status has been asserted. If not, the system informs theuser in step and waits for the motion control subsystem ON status to beasserted. Once the motion control subsystem ON status is asserted, aninitialization command is sent to the motion control subsystem in step226. The system follows up with a query in step 228 to determine if themotion control subsystem 171 completed its initialization in apredetermined amount of time in steps 230 and 232. If the motion controlsubsystem 171 does not complete its initialization process during thepredetermined time period, the user is informed in step 234 and furtherprogram execution is halted in step 236.

If the motion control system 171 completes its initialization processwithin the predetermined time period and responds with a Ready state instep 238, the system enters the idle mode in step and waits for a usercommand. In the idle mode, the system can execute Job File Management,Motion Control and Image Capture Commands as indicated in steps 242, 244and 246 as long as the motion control user interface program is runningas determined in step 248. Any time the motion control user interfaceprogram is exited, its state is saved in step 250 and the system returnsto step 236 and stops execution of program instructions.

Image Capture Mode

In this mode of operation, the user can specify the position that theimage capture device 176 is to move to by entering the desired absoluteor relative image capture device position. Automated, relative imagecapture device position increments and number of position increments canalso be :entered by the user. In this case, a single-image capture cycleconsists of positioning the image capture device 176 and capturing theviewed image. During the motion of the image capture device 176, theviewed image is displayed on the display of the host computer 164 inreal-time. Prior to capturing the viewed image, the host computer system164 queries the image capture device 176 via the image capture controlcard to determine if the image capture device 176 is ready to capturethe image. If the image capture device 176 is not ready, the hostcomputer system will wait before sending the next motion command to themotion control subsystem 171. After the image capture device 176captures the image, it will store the position of the entire axis in theJob File, and will send a command to the motion control subsystem 171 tomove to the next camera position, if a next position was specified.

When all the images are captured, the host computer system 164 willclose the Job File. The Job File will contain a list of all the camerapositions and respective images used in capturing all the images of a3-D object, to be further processed by the image capture andreconstruction program.

The Image Capture Mode logic flow is shown in FIG. 18. Turning to FIG.18, in the capture mode, the system queries the state of the imagecapture device 171 in step and determines in step 254 whether the imagecapture device 176 is ready. If the image capture device 176 is notready during a predetermined time-out period, as determined in step 256,an error message is provided to the user in step 258. The system thenreturns to the main program in step 260. However, during the time-outperiod, the system continuously checks the state of the image capturedevice 176 and loops back to step 252. When the image capture device 176is ready, a capture image command is sent to the image capturesubsystem.

Playback Mode

In this mode, the user selected Job File is played-back, so that all theimages needed to subsequently generate a 3-D image of a similar physicalpart, can be automatically captured. Prior to the Job File play-back, a“Home All Axis” command is sent by the host computer system 164 to themotion control subsystem 171 and the image capture device 176 is queriedto determine if it is ready to capture an image. The playback logic isillustrated in FIG. 17 and described below.

Description of the Motion Control User Interface Program

The motion control interface program facilitates operation of thenon-contact scanning system 162 by controlling the motion controlsubsystem 171 and by providing the internal communication interface tothe image capture subsystem via execution of user entered/initiatedcommands, or Job File playback. Commands are in turn sent to the motioncontrol subsystem 171 or the image capture subsystem, or both. Themotion control interface program command set is divided into two mainsections: Job File Control (JFC) and Machine Control (MC).

Description of Motion Control User Interface Program Commands Job FileControl

The Job File Control section divided into two sets of executablecommands, as shown in FIGS. 14 and 15. Job File Management, and Job FileExecution. Job File Management (JFM) is to facilitate the creation,loading, saving, deletion of Job Files (JF), and Job File Execution(JFE) is to facilitate the playback of previously created Job Files.

Job File Management (JFM) Commands:

1. New Job File (JFMC-001)

-   -   Allows the user to create and name a new Job File.

2. Open Job File (JFMC-002)

-   -   Allows the user the user to open an existing Job File.

3. Save Job File (JFMC-003)

-   -   Allows the user to save a newly created, or opened Job File.

4. Delete Job File (JFMC-004)

-   -   Allows the user to delete a selected Job File.

Job File Execution (JFE) Commands:

1. Playback Opened Job File, all File (JFEC-001)

-   -   This command allows the user to load a saved Job File for        subsequent playback, in its' entirety. Each Job File entry is        sequentially read and processed, to control the position that        fixture assembly 166, image capture device 176 axis is to move        to. Once the specified position is reached, a single image is        captured by the image capture device 176. This cycle is repeated        for all the entries in the Job File. The appropriate commands        are sent by the motion control user interface program to the        motion control subsystem 171 as each entry in the Job File is        read.

2. Playback Opened Job File, Single-Step (JFEC-002)

-   -   This command is the same as command JFEC-001, but each Job File        entry is single-stepped, under user control. This cycle may be        repeated until all the Job File entries are processed.

The control logic for the Job File Management and Job File Executioncommands is illustrated In FIGS. 16 and 17, respectively. Referringfirst to FIG. 16, the system checks for Job File Management and Job FileExecution commands in steps 264. If a Job File Management command isdetected, the system checks in steps 268 and 270 whether a new Job Filecommand is to be created or whether an existing job file is to beopened. If a new Job File is to be opened, the system prompts the userto select a Job File to be opened in step 272 and loads and opens theselected Job File in step 274.

For existing Job Files, the system checks whether the Job File commandis to save or delete an existing Job File in steps 276 and 278. If thecommand is to save a Job File, the Job File is saved in step. If thecommand is to delete a job file, the Job File is selected in step 282and deleted in step 284.

If the system determines in step 268 that a new Job File is to becreated, the user is prompted to name the new job file in step 286. Thesystem then checks whether the user selected job file name alreadyexists in step 288. If so, a user message is provided in step 290 soadvising the user and the system queries whether the existing Job Fileis to be opened in step 292 and executes the user command. On the otherhand, if the user selected Job File name does not already exist, a newJob File is created and opened in step 294.

Turning to FIG. 17, the system checks in steps 296 and 298 whether aPlay Back Job File All File or a Play Back Job File Single Step commandhas been issued. If a Play Back All File Command is issued, the Job Fileentry is read in step 300 and the checks in step 302 whether thespecified position has been reached by the fixture assembly 266 and asingle image is captured by the image capture subsystem. Once a singleimage is captured, a Play Back completion message is sent to the user instep 304. while the fixture assembly is getting to the desired position,position commands are sent to the motion control subsystem 171 in step306 until the specified position is reached, as determined in step 308.After the specified position is reached, the system calls the imagecapture and reconstruction program to have the image capture device 176capture an image in step 310.

If the command is a Job File single step command, the Job File entry isread in step 312. The user single steps through the Job File until thelast entry in the Job File is reached in step 314. For each step,position commands are sent to the motion control subsystem 171 to updatethe position of the fixture assemble 166 in step 316 until the finalposition is reached, as determined in step 318. Once the final positionis reached, the system calls the image capture and reconstructionprogram to have the image capture device 176 capture an image in step320.

For each step the Job File, a user prompt is generated in step 322.Unless the user enters a stop play back command, as determined in step324, subsequent Job File entries are read, as determined in step 326until the last entry in the job file is reached.

Machine Control

The Machine Control function is to initiate/monitor all internalcommands of the host computer system 164, and to control/monitor all thefixture assembly 166 axis motion/position, by sending specific commandsto one or more motion control modules, as discussed above. The motioncontrol modules control the appropriate motor(s) to move the imagecapture device to the specified spatial position. Query, Initializationand Image Capture Commands:

1. Query State of Image Capture Device, “Ready State” (QC-001)

-   -   This is an internal command within the host computer system 164        sent by the motion control user interface program to the image        capture subsystem via its image capture control card and the        image capture and reconstruction program to determine if the        image capture device 176 is ready to capture an image. If the        image capture device 176 responds with a “Ready State”, a        command to capture the image is sent by the motion control user        interface program to the image capture subsystem. If the image        capture subsystem does not respond with a “Ready State” within a        predefined time, the user is informed accordingly.

2. Capture Image (CIC-001)

-   -   This is an internal command within the host computer system 164        sent by the motion control user interface program to the image        capture subsystem, after the image capture subsystem has        asserted an image capture device “Ready State”, and instructs        the image capture subsystem to captured the viewed image.

3. Query State of Motion Control Sub-System, “ON/OFF State” (QC-002)

-   -   This is a command sent by the motion control user interface        program to the motion control user interface program, to query        the “ON/OFF State” of the motion control subsystem. The motion        control user interface program will wait for the assertion of        the “ON/OFF State” before sending an “Initialize motion control        subsystem” Command to the motion control system 171.

4. Query State of Motion Control Sub-System, “Ready State” (QC-003)

-   -   This is a query command sent by the motion control interface        program to the motion control subsystem 171 to determine if the        motion control subsystem 171 has properly initialized. After        proper initialization, the motion control subsystem 171 asserts        a “Ready State.” to inform the motion control interface program        of its' state. The motion control interface program will in turn        enter the “Idle Mode” of operation, and will wait for user's        entered commands. If the motion control subsystem 171 does not        assert a “Ready State” within a predefined time, the motion        control interface program will inform the user of motion control        subsystem 171 fault state.

5. Initialize MCSS (IC-001)

-   -   This is a command sent by the motion control interface program        to the motion control subsystem 171, after it receives the        “Ready State” assertion from the motion control subsystem 171.

Motion Control (MC) Commands:

1. Home All Axis (MCC-001)

-   -   This is a command sent by the motion control interface program        to the motion control subsystem 171, to send all fixture        assembly 166 axes to their respective home position. While the        fixture assembly 166 axes are in motion the motion control        interface program, via the motion control subsystem 171,        determines when the fixture assembly 166 axes have reached their        respective home-position.

2. Home Axis (MCC-002)

-   -   This command is the same as command MCC-001, but only the user        specified motion control subsystem 171 axis is moved to its home        position.

3. Move Axis by Distance or Angle (MCC-003)

-   -   This is a command sent by the motion control interface program        to the motion control subsystem 171, to move a user specified        fixture assembly 166 axis by a specified distance. The motion        control interface program, via the motion control subsystem 171,        determines when the specified fixture assembly 166 axis has        moved by the specified distance. If the Table Axis is specified,        the table is rotated by the specified angle.

4. Go-to 3-D Position, all Axis Except Table Axis (MCC-004)

-   -   This is a command sent by the motion control interface program        to the motion control subsystem 171, to move the appropriate        fixture assembly 166 axis to a user specified 3-D space        location. The motion control interface program, via the motion        control subsystem 171, determines when the fixture assembly 166        axes have reached the specified 3-D space location.

5. Go-to 3-D Position, not to Include Image Capture Device Focus Axis orTable Axis (MCC-005)

-   -   This command is the same as command MCC-004, but the image        capture device 176 focus axis remains at the same position.

6. Go-to Axis Position or Angle, Single Axis (MCC-006)

-   -   This command is the same as command MCC-004, but only a user        specified fixture assembly 166 axis is moved. If the Table Axis        is specified, the table is rotated by the specified angle.

7. Jog Axis Position or Angle (MCC-007)

-   -   This is a command sent by the motion control interface program        to the motion control subsystem 171, to “Jog” a user specified        fixture assembly 166 axis in a specified direction, by a        specified distance. If the Table Axis is specified, the table is        “Jogged” by the specified angle. Jog motion starts or stops by        pressing or releasing the HC input device.

Motion Control+Image Capture (MC+IC) Commands:

1. Increment Axis Distance or Angle, and Capture Image (MCICC-001)

-   -   This is a command sent by the motion control interface program        to the motion control subsystem 171, to move a specified fixture        assembly 166 axis by a specified distance. If the Table Axis is        specified, the table is rotated by the specified angle. After        axis motion stops, it will capture the image capture device 176        viewed image. On completion of this command, the motion control        interface program will wait for user input, to repeat the cycle.

2. Increment Axis by Distance or Angle, Capture Image, and Repeat(MCICC-002)

-   -   This is a command sent by the motion control interface program        to the motion control subsystem 171, to move a specified fixture        assembly 166 axis by a specified distance or angle. If the Table        Axis is specified, the table is rotated by the specified angle.        After axis motion stops, it will capture the image capture        device viewed image. This cycle will repeat for a user specified        number of times.

The machine control logic is shown in FIGS. 19A, 19B 20 and 21. Turningto FIGS. 19A and 97B, the system checks for motion control commands tothe motion control subsystem in steps 328, 330, 332, 334, 336, 338 and339. If a MCC-001 is detected in step 328, a Home All Axis Command issent to the motion control subsystem 171, as discussed above.Subsequently, a call is made to the motion control subsystem todetermine its status in step 280. If a MCC-002 command is detected instep 330, a user prompt is generated in step 344 to enter axis to home.After the user response is received, a home axis command is sent to themotion control subsystem 171 in step 346 and the system returns to step342. If a MCC-003 command is detected in step 332, a user prompt isgenerated in step 348 for the user to enter the axis and distance. Oncethe user response is detected, a move axis by distance command is sentto the motion control subsystem 171 in step 350 and the system returnsto step 342. If a MCC-004 command is detected in step 334, a user promptis generated in step 352 for the user to enter a 3 dimensional position.Once the user response is detected, a go to 3 dimensional position allaxis command is sent to the motion control subsystem 171 in step 354 andthe system returns to step 342. If a MCC-005 command is detected in step336, a user prompt is generated in step 356 for the user to enter a 3dimensional position not including the focus axis. Once the userresponse is detected, a go to 3 dimensional position command is sent tothe motion control subsystem 171 in step 358 and the system returns tostep 342. If a MCC-006 command is detected in step 338, a user prompt isgenerated in step 360 for the user to enter the axis and distance. Oncethe user response is detected, a go to axis and position command is sentto the motion control subsystem 171 in step 362 and the system returnsto step 342. If a MCC-007 command is detected in step 339, a user promptis generated in step 364 for the user to enter the axis to jog and thejog distance and checks the in step 366. Once the user response isdetected, the system checks whether a jog axis has been specified instep 366. If so, a call is made to the motion control subsystem 171 instep 368 and a send jog axis command is sent to the motion controlsubsystem 171 in step 370. The system returns to step 372 and promptsthe user for another jog axis or stop jog cycle command.

[00821 Turning to FIG. 20, the system checks for MCICC-001 andMCCICC-002 commands in steps 372 and 374. If a MCCICC-001 command isdetected, a user prompt is generated in step 376 requesting the user toenter axis and distance increment information. After the user responseis detected, a send increment axis command is sent to the motion controlsubsystem 171 in step 378. Subsequently calls are made in steps 380 and382 to check the status of the motion control subsystem 171 and capturethe image.

If a MCICC-002 command is detected in step 374, a user prompt isgenerated in step 384 requesting the user to enter the axis and distanceincrement and to enter the number of repeat cycles in step 385. Afterthe user information is detected, an increment axis command is sent tothe motion control subsystem 171 in step and a call is made to determinethe status of the motion control subsystem 171 in step 388. In step 390,the system checks if the repeat cycles are done. If not, the systemloops back to step 386 and repeats steps 386 and 388.

FIG. 21 illustrates the control logic for the motion control subsystemstatus function. Each time a call is made to check the status of themotion control subsystem 171, the system checks in step 392 whether therequested motion is complete. If so, the system returns that the motionis complete. If not, the system checks in step 394 whether the requestedmotion has been completed during a predetermined time period. If not anerror message is sent to the user in step 396.

Motion Control Subsystem Schematic

An exemplary schematic diagram for the motion control subsystem 171 isillustrated in FIG. 13. A key for the various components is providedbelow.

-   50 Host Computer-   52 Host Computer Display Unit-   54 User to Host Computer Input Device-   56 Image Capture Card-   58 Host Computer to Motion Control Sub-system Interface/Signal Link-   60 Host Computer to Motion Image Capture Device Interface/Signal    Link-   62 Image Capture Device-   70 Semi-Spherical Gantry-   72 Motorized Multi-axis Platform-   74 Power Disconnect Box-   76 Gantry Access Doors-   78 Gantry Access Door, Interlock Switch-   80 Motion Control Sub-system Panel-   82 Motion Control Sub-system Panel Door-   84 Motion Control Sub-system Panel Door, Interlock Switch-   86 User Control Panel-   88 ON/OFF Switch with Indicator-   90 Emergency Stop Switch-   92 Gantry In-Motion Indicator-   100 X-Axis Home Position Sensor-   102 X-Axis Bumper Sensor-   104 Y-Axis Home Position Sensor-   106 Y-Axis Bumper Sensor-   108 AR-Axis (Arm Rotation Axis) Home Position Sensor-   110 AR-Axis (Arm Rotation Axis) Bumper Sensor-   112 R-Axis (Rotary Axis) Home Position Sensor-   114 Z-Axis (Image Capture Device Focus Axis) Home Position Sensor-   116 Z-Axis (Image Capture Device Focus Axis) Bumper Sensor-   130 Power Disconnect Switch-   132 Main Fuses-   134 Power Step-Down transformer-   136 Line Filter-   138 Power Supply-   140 Relay Logic Panel-   142 X-Axis and Y-Axis Motion Control Module-   144 AR-Axis (Arm Rotation Axis) and Rotary-Axis Motion Control    Module-   146 Z-Axis (Image Capture Device Focus Axis) Motion Control Module-   148 X-Axis Motor-   150 Y-Axis Motor-   152 AR-Axis (Arm Rotation Axis) Motor-   154 R-Axis (Rotary Axis) Motor-   156 Z-Axis (Image Capture Device Focus Axis) Motor-   158 Host Computer to Motion Control Sub-system Interface/Signal    Connector

Operation

Operation of the non-contact scanning system is user initiated byapplying power to both the motion control subsystem 171 and the hostcomputer system 164, via their respective ON/OFF switch. Once the hostcomputer system 164 is ON, it will automatically load and run the motioncontrol user interface program. The turn ON order is not important,since operation of the fixture assembly 166 can only take place afterthe host computer system 164 has completed the “Initialization Mode ofOperation.”

After the motion control subsystem 171 has properly initialized, themotion control user interface program will enter the “Idle Mode ofOperation”. In this mode, the motion control user interface program sitsidle, and waits for a user command. Once a command is entered, themotion control user interface program will interpret the command, andwill responds accordingly, to execute the command. The user can enterone of several commands to create, open, save, delete, or execute a JobFiles. The user can also enter one of several commands to manually orautomatically (via execution of a Job File) control the motion of thefixture assembly 166 axis, and the image capture of an object, restingon the fixture assembly 166 table axis

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. Thus, it is to beunderstood that, within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described above.

1. (canceled)
 2. A method for scanning a three dimensional object, themethod comprising the steps of: (a) securing the three dimensionalobject to a fixture assembly having at least three degrees of freedom ofmovement and a scanner configured to move along an arcuate path relativeto the three dimensional object: and (b) manipulating the movement ofthe fixture and the scanner so that a three dimensional image of saidobject can be made.
 3. The method as recited in claim 2 wherein step (a)comprises: (a) securing the three dimensional object to a fixtureassembly having at least three degrees of freedom of movement and ascanner configured to move along an arcuate path relative to the threedimensional object: and further configured to move relative to a linearaxis.
 4. A method for scanning a three dimensional object, the methodcomprising the steps of: (a) securing the three dimensional object to afixture assembly having a scanner configured to move along an arcuatepath relative to the three dimensional object: and (b) manipulating themovement of the fixture and the scanner so that a three dimensionalimage of said object can be made.